/*
 * Copyright (c) 2016 Zibin Zheng <znbin@qq.com>
 * All rights reserved
 */

#include "multi_button.h"

#define EVENT_CB(ev) \
    if (handle->cb[ev]) handle->cb[ev]((void *)handle)

/*!< The maximum value of the repeat counter */
#define PRESS_REPEAT_MAX_NUM 15

// button handle list head.
static struct Button *head_handle = NULL;

static void button_handler(struct Button *handle);

/**
 * @brief  Initializes the button struct handle.
 * @param  handle: the button handle struct.
 * @param  pin_level: read the HAL GPIO of the connected button level.
 * @param  active_level: pressed GPIO level.
 * @param  button_id: the button id.
 * @retval None
 */
void button_init(struct Button *handle, uint8_t (*pin_level)(uint8_t), uint8_t active_level,
                 uint8_t button_id) {
    memset(handle, 0, sizeof(struct Button));
    handle->event = (uint8_t)NONE_PRESS;
    handle->hal_button_Level = pin_level;
    handle->button_level = handle->hal_button_Level(button_id);
    handle->active_level = active_level;
    handle->button_id = button_id;
}

/**
 * @brief  Attach the button event callback function.
 * @param  handle: the button handle struct.
 * @param  event: trigger event type.
 * @param  cb: callback function.
 * @retval None
 */
void button_attach(struct Button *handle, PressEvent event, BtnCallback cb) {
    handle->cb[event] = cb;
}

/**
 * @brief  Inquire the button event happen.
 * @param  handle: the button handle struct.
 * @retval button event.
 */
PressEvent get_button_event(struct Button *handle) { return (PressEvent)(handle->event); }

/**
 * @brief  Button driver core function, driver state machine.
 * @param  handle: the button handle struct.
 * @retval None
 */
static void button_handler(struct Button *handle) {
    uint8_t read_gpio_level = handle->hal_button_Level(handle->button_id);

    // ticks counter working..
    if ((handle->state) > 0) handle->ticks++;

    /*------------button debounce handle---------------*/
    if (read_gpio_level != handle->button_level) {  // not equal to prev one
        // continue read 3 times same new level change
        if (++(handle->debounce_cnt) >= DEBOUNCE_TICKS) {
            handle->button_level = read_gpio_level;
            handle->debounce_cnt = 0;
        }
    } else {  // level not change ,counter reset.
        handle->debounce_cnt = 0;
    }

    /*-----------------State machine-------------------*/
    switch (handle->state) {
        case 0:
            if (handle->button_level == handle->active_level) {  // start press down
                handle->event = (uint8_t)PRESS_DOWN;
                EVENT_CB(PRESS_DOWN);
                handle->ticks = 0;
                handle->repeat = 1;
                handle->state = 1;
            } else {
                handle->event = (uint8_t)NONE_PRESS;
            }
            break;

        case 1:
            if (handle->button_level != handle->active_level) {  // released press up
                handle->event = (uint8_t)PRESS_UP;
                EVENT_CB(PRESS_UP);
                handle->ticks = 0;
                handle->state = 2;
            } else if (handle->ticks > LONG_TICKS) {
                handle->event = (uint8_t)LONG_PRESS_START;
                EVENT_CB(LONG_PRESS_START);
                handle->state = 5;
            }
            break;

        case 2:
            if (handle->button_level == handle->active_level) {  // press down again
                handle->event = (uint8_t)PRESS_DOWN;
                EVENT_CB(PRESS_DOWN);
                if (handle->repeat != PRESS_REPEAT_MAX_NUM) {
                    handle->repeat++;
                }
                EVENT_CB(PRESS_REPEAT);  // repeat hit
                handle->ticks = 0;
                handle->state = 3;
            } else if (handle->ticks > SHORT_TICKS) {  // released timeout
                if (handle->repeat == 1) {
                    handle->event = (uint8_t)SINGLE_CLICK;
                    EVENT_CB(SINGLE_CLICK);
                } else if (handle->repeat == 2) {
                    handle->event = (uint8_t)DOUBLE_CLICK;
                    EVENT_CB(DOUBLE_CLICK);  // repeat hit
                }
                handle->state = 0;
            }
            break;

        case 3:
            if (handle->button_level != handle->active_level) {  // released press up
                handle->event = (uint8_t)PRESS_UP;
                EVENT_CB(PRESS_UP);
                if (handle->ticks < SHORT_TICKS) {
                    handle->ticks = 0;
                    handle->state = 2;  // repeat press
                } else {
                    handle->state = 0;
                }
            } else if (handle->ticks > SHORT_TICKS) {  // SHORT_TICKS < press down hold time <
                                                       // LONG_TICKS
                handle->state = 1;
            }
            break;

        case 5:
            if (handle->button_level == handle->active_level) {
                // continue hold trigger
                handle->event = (uint8_t)LONG_PRESS_HOLD;
                EVENT_CB(LONG_PRESS_HOLD);
            } else {  // released
                handle->event = (uint8_t)PRESS_UP;
                EVENT_CB(PRESS_UP);
                handle->state = 0;  // reset
            }
            break;
        default:
            handle->state = 0;  // reset
            break;
    }
}

/**
 * @brief  Start the button work, add the handle into work list.
 * @param  handle: target handle struct.
 * @retval 0: succeed. -1: already exist.
 */
int button_start(struct Button *handle) {
    struct Button *target = head_handle;
    while (target) {
        if (target == handle) return -1;  // already exist.
        target = target->next;
    }
    handle->next = head_handle;
    head_handle = handle;
    return 0;
}

/**
 * @brief  Stop the button work, remove the handle off work list.
 * @param  handle: target handle struct.
 * @retval None
 */
void button_stop(struct Button *handle) {
    struct Button **curr;
    for (curr = &head_handle; *curr;) {
        struct Button *entry = *curr;
        if (entry == handle) {
            *curr = entry->next;
            //			free(entry);
            return;  // glacier add 2021-8-18
        } else {
            curr = &entry->next;
        }
    }
}

/**
 * @brief  background ticks, timer repeat invoking interval 5ms.
 * @param  None.
 * @retval None
 */
void button_ticks(void) {
    struct Button *target;
    for (target = head_handle; target; target = target->next) {
        button_handler(target);
    }
}
